I started taking adderall (amphetamine) 20 mg per day and I am worried about damaging T production since this happens in animal (mice) models.
does anyone have knowledge about this?
I have tested my blood Total Testosterone 2 times with very different results. does anybody know if you would expect a difference of 135 ng/dl between the different test methods called liquid chromatography/tandem mass spectronomy and then immunoassay?
here are my results

For instance, if the 700 was at 8 AM and the 564 was at 2 PM, the swing would probably be mostly attributable to the timing of the test. Your testosterone levels are at their highest in the morning and fall during the day.

Then I would be concerned about a 136 point drop.
I also worry about this, as I have ADD and am trying to get back on medication. I had success with Concerta for attention but am not sure what it did to my T levels.

Even on the same blood sample, different labs can often show very different results (commonly different labs will disagree by 25-30% when testing the same sample; even the same lab will get different results when running the same sample twice). Also, a variation of 140 points from day to day (as in your tests, even if they were taken at the same time of day) is very much within the normal variability. Men just don’t have the same levels every day.

The reason that you should not change labs is that you then do not know if changes are from drugs/doses or health issues or simply from the differences between labs. On TRT, you should always do labs with same timing relative to injections.

They are both quest diagnostics but to test methods. The first is mass strometry/lc and the second is immunoassay. One costs less money so I changed methods. Could it be that immunoassay is just way less sensitive in measuring total T?